How to remove the last update on iPhone

You cannot go back to a previous iOS version once you have updated. If you are not a fan of the Liquid Glass, check the page below for options to lessen the effect. I found them very helpful.

Liquid Glass - Love It Or Hate It - Apple Community

If you have other specific concerns, let us know.

You cannot do that. Further, you should never want to do that as the latest iOS update provides, among other things, critical security updates.

Perhaps we can assist if you tell us your specific technical issues.

Limnos wrote:

Apple is still supplying iOS18 updates (About the security content of iOS 18.7.3 and iPadOS 18.7.3 - Apple Support) to devices that have not been upgraded to the iOS26..

Actually that is no longer correct.

From this thread:

iPhone 12 not offered iOS 18.7.3 update, … - Apple Community

See Niel’s response:

”Apple stopped signing 18 for models capable of 26, so it's no longer possible to update yours to that.”

The latest update does, but that is a difference between updates and upgrades.

Apple is still supplying iOS18 updates (About the security content of iOS 18.7.3 and iPadOS 18.7.3 - Apple Support) to devices that have not been upgraded to the iOS26..

Agreed.

But readers of this thread please note:

Apple Pushes iPhone Users Still on iOS 18 to Upgrade to iOS 26